Scroll compressor

ABSTRACT

A scroll compressor includes a housing, an Oldham ring slidable on the housing by a first key mechanism, a fixed scroll, and an orbiting scroll slidable on the Oldham ring by a second key mechanism. The first key mechanism includes a first key provided to the Oldham ring and a first key groove formed in the housing. The first key protrudes toward the housing and radially inwardly from a ring portion. The housing includes a flange with a facing portion. The fixed scroll is fixed to the flange. The facing portion has an orbiting scroll facing surface, and an annular opening formed around the orbiting scroll facing surface and movably housing the ring portion. The first key groove is formed adjacent to a back surface of the facing portion opposite to the orbiting scroll facing surface so as to extend radially inwardly from the annular opening.

TECHNICAL FIELD

The present disclosure relates to a scroll compressor provided with acompression mechanism having a fixed scroll and an orbiting scroll, andin particular, to a structure of allowing the compression mechanism tohold an Oldham ring that is a mechanism preventing the orbiting scrollfrom rotating on its axis.

BACKGROUND ART

In conventional scroll compressors, an Oldham ring (100) is typicallyused to allow revolution of an orbiting scroll (not illustrated) whilesubstantially preventing rotation of the orbiting scroll on its axis, asillustrated in FIG. 17 that is a plan view of a housing and the Oldhamring, FIG. 18 that is a cross-sectional view taken along lineXVIII-XVIII of FIG. 17, FIG. 19 that is a plan view of the Oldham ring,and FIG. 20 that is a cross-sectional view taken along line XX-XX ofFIG. 19. In general, the Oldham ring (100) is comprised of a ringportion (101) and keys (102, 103) which are integrally formed together.The Oldham ring (100) includes a pair of keys (102) and another pair ofkeys (103), the keys (102) being disposed on a surface of the ringportion (101) closer to a housing (110), the keys (103) being disposedon another surface of the ring portion (101) closer to the orbitingscroll. The pair of keys (102) protrudes from the surface of the ringportion (101) closer to the housing (110) in a direction perpendicularto the surface. The other pair of keys (103) protrude from the surfaceof the ring portion (101) closer to the orbiting scroll in a directionperpendicular to the surface. The housing (110) is provided with anannular opening (111.) movably housing the ring portion (101) and a keygroove (112) engaged with the keys (102).

Patent Document 1 discloses, as a modification of the above structure, astructure in which the keys (102, 103) are disposed so as to protruderadially outwardly from the ring portion (101), as illustrated in FIGS.21 to 24.

Further, Patent Document 2 discloses, as illustrated in FIGS. 25 to 28,a structure in which one pair of keys (102) of the pair of keys (102)and the pair of keys (103) of the Oldham ring (100) are formed toprotrude radially inwardly from the ring portion (101), and not toprotrude in the direction perpendicular to the surface.

CITATION LIST Patent Document

[Patent Document 1] Japanese Unexamined Patent Publication No.2010-185462

[Patent Document 2] Japanese Unexamined Patent Publication No.S63-138181

SUMMARY OF THE INVENTION Technical Problem

The typical configuration of the Oldham ring (100) shown in FIGS. 17 to20 has a small sliding area between the key (102) and the key groove(112), and thus, a contact pressure of the key sliding surface isincreased, resulting in insufficient strength of the keys (102) of theOldham ring (100).

In the configuration of Patent Document 1, as illustrated in FIG. 21,the outer periphery of the housing (110) may have to be provided with anotch (115), resulting in decreased strength of the housing (110). Inaddition, the keys (102, 103) are formed in the radially outside of thering portion (101), and thus, a moment applied to the keys (102, 103) isincreased, resulting in decreased strength of the Oldham ring (100).

Further, in the configuration of Patent Document 2, as illustrated inFIG. 25, the key groove (112) of the housing (110) is formed on anorbiting scroll facing surface (120) on which the orbiting scroll (notillustrated) faces the surface of the housing (110), and thus, theeffective area of the orbiting scroll facing surface (120) is decreased,resulting in increased contact pressure. Also, in a situation where theorbiting scroll facing surface (120) in the scroll compressor isprovided with a sealing ring, if the key groove (112) is intended to beformed in the radially inside of the orbiting scroll facing surface(120) relative to Oldham ring (100), and in particular, if the area ofthe orbiting scroll facing surface (120) is small, the sealing ring mayhinder the formation of the key groove (112).

In view of the foregoing background, it is therefore an object of thepresent invention to prevent the strength of, e.g., a housing and anOldham ring from decreasing too much while preventing the size of anorbiting scroll facing surface from decreasing too much.

Solution to the Problem

A first aspect of the present disclosure is directed to a scrollcompressor including: a housing (23) into which a drive shaft (40) isinserted: an Oldham ring (50) configured to be slidable on the housing(23) by a first key mechanism (51) in a first direction perpendicular toan axial center of drive shaft (40); a fixed scroll (21) fixed to thehousing (23); and an orbiting scroll (22) meshing with the fixed scroll(21) and configured to be slidable on the Oldham ring (50) by a secondkey mechanism (52) in a second direction perpendicular to the axialcenter of drive shaft (40), the first key mechanism (51) including afirst key (54) provided to the Oldham ring (50) and a first key groove(61) formed in the housing (23).

In the scroll compressor, the first key (54) protrudes from the ringportion (53) of the Oldham ring (50) toward the housing (23), andfurther protrudes in a radially inward direction of the ring portion(53), the housing (23) includes a flange (23 a) to which the fixedscroll (21) is fixed and which includes a facing portion (71) having apredetermined thickness and having an orbiting scroll facing surface(70) facing the orbiting scroll (22), and an annular opening (72) formedaround the orbiting scroll facing surface (70) and movably housing thering portion (53), and the first key groove (61) is formed in a positionadjacent to a back surface of the facing portion (71) opposite to theorbiting scroll facing surface (70) so as to extend radially inwardlyfrom the annular opening (72). In this configuration, the orbitingscroll facing surface (70) facing the orbiting scroll (22) may be incontact with (slide on) the orbiting scroll (22) or may be spaced apartfrom (not slide on) the orbiting scroll (22).

According to the first aspect, the first key groove (61) formed in theposition adjacent to the back surface of the facing portion (71) engageswith the first key (54) of the Oldham ring (50), allowing the Oldhamring (50) to operate. In this configuration, the first key (64)protrudes from the ring portion (53) of the Oldham ring (50) toward thehousing (23) and further protrudes in the radially inward direction ofthe ring portion (53). This can sufficiently increase the area of thesliding surface between the first key (54) and the first key groove (61)to reduce a contact pressure of the key sliding surface. Also, since thefirst key (54) protrudes in the radially inward direction of the Oldhamring (50), the outer periphery of the housing (23) does not have to benotched, and the moment of the first key (54) can be reduced. Further,the first key groove (61) is formed in the position adjacent to the backside of the orbiting scroll facing surface (70) (in the positionadjacent to the back surface of the facing portion (71)), and thus, thefirst key groove (61) does not hinder the formation of the sealing ring.

A second aspect of the present disclosure is an embodiment of the firstaspect. In the second aspect, the first key (54) includes a pair offirst keys (54) opposed to each other by 180° on the Oldham ring (50),and an interval (A) between the pair of the first keys (54) is smallerthan an outer diameter (B) of the facing portion (71) of the housing(23), and a thickness (C) of the ring portion (53) is larger than athickness (D) of the facing portion (71) of the housing (23).

The second aspect satisfies the above dimension relationship, making itpossible to easily attach the Oldham ring (50) to the housing (23) alongan oblique direction, as illustrated in FIGS. 10 and 11.

A third aspect of the present disclosure is an embodiment of the firstor second aspect of the present disclosure. In the third aspect, theback surface of the facing portion (71) is a tilted surface (71 a) suchthat a thickness of the facing portion (71) increases toward an innerperiphery of the facing portion (71).

According to the third aspect, the back surface of the facing portion(71) is the tilted surface (71 a), and thus, when the Oldham ring (50)is attached to the housing (23), the first key (54) can be easilyinserted into the first key groove (61).

A fourth aspect of the present disclosure is an embodiment of the first,second, or third aspect of the present disclosure. In the fourth aspect,the first key groove (61) is a groove opened on a hack surface of theflange (23 a) of the housing (23).

According to the fourth aspect, the first key (54) engages with thefirst key groove (61) opened on the back surface of the flange (23 a) ofthe housing (23), allowing the Oldham ring (50) to operate.

A fifth aspect of the present disclosure is an embodiment of the first,second, or third aspect of the present disclosure. In the fifth aspect,the first key groove (61) is a groove opened on an outer peripheralsurface of the flange (23 a) of the housing (23).

According to the fifth aspect, the first key (54) engages with the firstkey groove (61) opened on the outer peripheral surface of the flange (23a) of the housing (23), allowing the Oldham ring (50) to operate.

A sixth aspect of the present disclosure is an embodiment of the first,second, or third. aspect of the present disclosure. In the sixth aspect,the facing portion (71) is configured as a separate member differentfrom the housing (23) and fixed to a main body of the housing (23).

According to the sixth aspect, the first key groove (61) is formed byfixing the facing portion (71) configured as a separate member to themain body of the housing (23), and the first key (54) engages with thefirst key groove 61), allowing the Oldham ring (50) to operate.

Advantages of the Invention

According to the first aspect of the present disclosure, the first key(64) protrudes from the ring portion (53) of the Oldham ring (50) towardthe housing (23) and further protrudes in the radially inward directionof the ring portion (53). This can sufficiently increase the area of thesliding surface between the first key (54) and the first key groove(61), and reduce a contact pressure of the key sliding surfacecontributing to preventing insufficient strength of the first key (54)of the Oldham ring (50). Also, the first key (54) protrudes in thedirection radially inward of the Oldham ring (50), and the outerperiphery of the housing (23) does not have to be notched. This canreduce the moment of the first key (54), and prevent the strength of theOldham ring (50) from decreasing too much. Further, since the first keygroove (61) is formed in the position adjacent to the back side of theorbiting scroll facing surface (70) (in the position adjacent to theback surface of the facing portion (71)), the first key groove (61) doesnot hinder the formation of the sealing ring, and it is possible to usethe seal ring (50) in a configuration in which the first key (54) andthe first key groove (61) engage with each other.

According to the second aspect of the present disclosure, the interval(A) between the pair of the first keys (54) is smaller than the outerdiameter (B) of the facing portion (71) of the housing (23), and thethickness (C) of the ring portion (53) is larger than the thickness (D)of the facing portion (71) of the housing (23). Thus, as illustrated inFIGS. 10 and 11, the Oldham ring (50) can be easily attached to thehousing (23) along an oblique direction. Accordingly, the Oldham ring(50) does not have to be made large, making it possible to reduce thesize of the mechanism.

According to the third aspect of the present disclosure, the backsurface of the facing portion (71) is the tilted surface (71 a), andthus, when the Oldham ring (50) is attached to the housing (23), thefirst key (54) can be easily inserted into the first key groove (61),improving ease of attachment.

According to the fourth aspect of the present disclosure, the first keygroove (61) is a groove opened on the back surface of the flange (23 a)of the housing (23), easily forming the first key groove (61).

According to the fifth aspect of the present disclosure, the first keygroove (61), which is a groove opened on the outer peripheral surface ofthe flange (23 a) of the housing (23), can be easily formed.

According to the sixth aspect of the present disclosure, the first keygroove (61) can be easily formed by fixing the facing portion (71)configured as a separate member to the main body of the housing (23).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical cross-sectional view of a scroll compressoraccording to an embodiment of the present disclosure.

FIG. 2 is a plan view illustrating a state in which an Oldham ring isbeing attached to a housing.

FIG. 3 is a cross-sectional view taken along line III-III FIG. 2.

FIG. 4 is a plan view of the Oldham ring.

FIG. 5 is a cross-sectional view taken along line V-V of FIG. 4.

FIG. 6 is a plan view illustrating a state in which the Oldham ring isbeing attached to the housing having a body whose back surface side isopened, and provided with a first key groove.

FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6.

FIG. 8 illustrates a relationship between the dimension of the housingand the dimension of the Oldham ring.

FIG. 9 illustrates a portion of FIG. 8 on an enlarged scale.

FIG. 10 is a plan view illustrating a first state in which the Oldhamring is being attached to the housing.

FIG. 11 is a plan view illustrating a second state in which the Oldhamring is being attached to the housing.

FIG. 12 is a partially enlarged cross-sectional view of a housingaccording to a first variation.

FIG. 13 is a partially enlarged cross-sectional view of a housingaccording to a second variation.

FIG. 14 is a plan view of a housing and an Oldham ring according to athird variation.

FIG. 15 is a cross-sectional view taken along line XV-XV of FIG. 14.

FIG. 16 is a cross-sectional view of a main part of a compressoraccording to another embodiment.

FIG. 17 is a plan view illustrating a state in which an Oldham ring isbeing attached to a housing according to a first conventional example.

FIG. 18 is a cross-sectional view taken along line XVIII-XVIII of FIG.17.

FIG. 19 is a plan view of the Oldham ring of the first conventionalexample.

FIG. 20 is a cross-sectional view taken along line XX-XX of FIG. 19.

FIG. 21 is a plan view illustrating a state in which an Oldham ring isbeing attached to a housing according to a second conventional example.

FIG. 22 is a cross-sectional view taken along line XXII-XXII of FIG. 21.

FIG. 23 is a plan view of the Oldham ring of the second conventionalexample.

FIG. 24 is a cross-sectional view taken along line XXIV-XXIV of FIG. 23.

FIG. 25 is a plan view illustrating a state in which an Oldham ring isbeing attached to a housing according to a third conventional example.

FIG. 26 is a cross-sectional view taken along line XXVI-XXVI of FIG. 25.

FIG. 27 is a plan view of the Oldham ring of the third conventionalexample.

FIG. 28 is a cross-sectional view taken alone line XXVIII-XXVIII of 27.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure will now be described in detailwith reference to the drawings.

A scroll compressor according to this embodiment is provided to, e.g., arefrigerant circuit of an air conditioner performing a vapor compressionrefrigeration cycle, and compresses a low-pressure refrigerant that hasbeen sucked from an evaporator to discharge it into a condenser.

As illustrated in FIG. 1, the scroll compressor (1) is a so-calledhermetic compressor. This scroll compressor (1) includes a casing (10)that is a hermetically-sealed container with a vertically orientedcylindrical shape. The casing (10) includes a body (11) with avertically oriented cylindrical shape, an upper end plate (12) fixed tothe upper end of the body (11), and a lower end plate (13) fixed to thelower end of the body (11).

This casing (10) houses a compression mechanism (20) compressing arefrigerant, and an electric motor (45) driving the compressionmechanism (20). The electric motor (45) is disposed below thecompression mechanism (20), and is coupled to the compression mechanism(20) through a drive shaft (40) that is a rotational shaft. The electricmotor (45) is implemented as a brushless DC motor controlled by aninverter to adjust a rotational speed to be variable.

A discharge pipe (5) passes through and is attached to the upper endplate (12) that is a top of the casing (10). This discharge pipe (15)has its terminal end (the lower end in the figure) connected to thecompression mechanism (20). A suction pipe (14) passes through and isattached to the body (11) of the casing (10). This suction pipe (14) hasits terminal end (the right end in the figure) open toward a spacebetween the compression mechanism (20) and the electric motor (45) inthe casing (10).

The drive shaft (40) is disposed on the vertical center line of theeasing (10). The drive shaft (40) is a crank shaft including a mainshaft portion (41) and an eccentric portion (42). The eccentric portion(42) has a smaller diameter than the main shaft portion (41), and isformed on the upper surface of the main shaft portion (41). Theeccentric portion (42) is eccentric from the axial center of the mainshaft portion (41) by a predetermined dimension, and constitutes aneccentric pin.

A lower bearing holder (48) is fixed to a portion adjacent to the lowerend of the body (11) of the casing (10). This lower bearing holder (48)rotatably supports the lower end of the main shaft portion (41) of thedrive shaft (40) through a sliding bearing (48 a).

The interior of the drive shaft (40) is provided with an oil supplypassage (44) extending vertically. The lower end of the main shaftportion (41) is provided with an oil supply pump (43). This oil supplypump (43) sucks refrigerating machine oil from the bottom of the casing(10). The refrigerating machine oil passes through the oil supplypassage (44) of the drive shaft (40) to be supplied to the slidingportion of the compression mechanism (20) and the bearing of the driveshaft (40).

The electric motor(45) is comprised of a stator (46) and a rotor (47).The stator (46) is fixed to the body (11) of the casing (10). The rotor(47) is coupled to the main shaft portion (41) of the drive shaft (40)to drive the drive shaft (40) in rotation.

The compression mechanism (20) includes a fixed scroll (21), an orbitingscroll (22), and a housing (23) fixing and supporting the fixed scroll(21). The fixed scroll (21) and the orbiting scroll (22) respectivelyinclude spiral laps (21 b, 22 b) meshing with each other on end plates(21 a, 22 a). The compression mechanism (20) is configured such that theorbiting scroll (22) rotates eccentrically relative to the fixed scroll(21).

The housing (23) is comprised of a main body (flange) (23 a) and abearing holder (23 b). The main body (23 a) is formed to be verticallycontinuous with the bearing holder (23 b), and the main body (23 a) isfitted into and coupled to the body (11) of the casing (10). The bearingholder (23 b) has a smaller diameter than the main body (23 a), andprotrudes downward from the main body (23 a). The bearing holder (23 b)rotatably supports the main shaft portion (41) of the drive shaft (40)through a sliding bearing (23 c).

The fixed scroll (21) is comprised of a fixed end plate (21 a), a fixedlap (21 b), and an edge portion (21 c). The fixed end plate (21 a) isformed to have a substantially disk shape. The fixed lap (21 b) standsnear the middle portion of the lower surface of the fixed end plate 21a), and is integrally formed with the fixed end plate (21 a). The fixedlap (21 b) is formed to have a spiral wall shape with a constant height.The edge portion (21 c) is a wall extending downward from the outerperipheral portion of the fixed end plate (21 a), and has a lowersurface overlapping with the upper surface of the main body (23 a) ofthe housing (23) to be fixed to the housing (23).

The orbiting scroll (22) is comprised of an orbiting end plate (22 a),an orbiting lap (22 b), and a boss (22 c). The orbiting end plate (22 a)is formed to have a substantially disk shape. The orbiting lap (22 b)stands on upper surface of the orbiting end plate (22 a), and isintegrally formed with the orbiting end plate (22 a). The orbiting lap(22 b) is formed to have a spiral wall shape with a constant height, andto mesh with the fixed lap (21 b) of the fixed scroll (21).

The upper end of the fixed end plate (21 a) is provided with adepression (21 g), and a discharge cover (27) is attached to the uppersurface of the fixed end plate (21 a) to cover the depression (21 g). Aspace where the depression (21 g) is covered with the discharge cover(27) is a discharge chamber (28) communicating with the discharge pipe(15). A middle lower portion of the fixed end plate a) is provided witha discharge port (26) communicating with the discharge chamber (28), andthe discharge port (26) communicates with a compression chamber formedbetween the fixed lap (21 b) and the orbiting lap (22 b). In thisembodiment, in the interior of the casing (10), both upper and lowerspaces (16) and (17) of the housing (23) are low-pressure spaces filledwith a low-pressure refrigerant.

The boss (22 c) extends downwardly from the lower surface of theorbiting end plate (22 a), and integrally formed with the orbiting endplate (22 a). The eccentric portion (42) of the drive shaft (40) isinserted into the boss (22 c) through a sliding bearing (22 d).Therefore, if the drive shaft (40) rotates, the orbiting scroll (22)revolves around the axial center of the main shaft portion (41). Therevolution radius of the orbiting scroll (22) is the same as theeccentricity of the eccentric portion (42), i.e., a distance from theaxial center of the main shaft portion (41) to the axial center of theeccentric portion (42).

The orbiting end plate (22 a) is disposed in a first recess (23 d)provided to the upper end of the housing (23). The boss (22 c) isdisposed in a second recess (a crank chamber) (23 e) provided to themain body (23 a) of the housing (23). The Oldham ring (50) is disposedbetween the orbiting end plate (22 a) and the housing (23) to preventthe orbiting scroll (22) from rotating on its axis.

FIG. 2 is a plan view illustrating a state in which the Oldham ring (50)is being attached to the housing (23) and FIG. 3 is a cross-sectionalview taken along line III-III of FIG. 2. FIG. 4 is a plan view of theOldham ring (50), and FIG. 5 is a cross-sectional view taken along lineV-V of FIG. 4. The Oldham ring (50) is configured to be slidable on thehousing (23), into which the drive shaft (40) is inserted, by a firstkey mechanism (51) in a first direction perpendicular to the axialcenter of drive shaft (40). The orbiting scroll (22) meshes with thefixed scroll (21) fixed to the housing (23), and is configured to beslidable on the Oldham ring (50) by a second key mechanism (52) in asecond direction perpendicular to the axial center of drive shaft (40).

The Oldham ring (50) has a ring portion (53). The first key mechanism(51) is comprised of a first key (54) provided to the ring portion (53)and a first key groove (61) formed in the housing (23). The second keymechanism (52) is comprised of a second key (55) provided to the ringportion (53) and a second key groove (62) formed in the orbiting scroll(22).

A reciprocating motion of the first key (54) in the first key groove(61) and a reciprocating motion of the second key (55) in the second keygroove (62) are synthesized to allow the orbiting scroll (22) engagingwith the second key (55) to rotate on its axis, not to revolve aroundthe fixed scroll (21) fixed to the housing (23).

As illustrated in FIGS. 2 to 5, the first key (54) protrudes from thering portion (53) of the Oldham ring (50) toward the housing (23) (awayfrom the orbiting scroll (22)), and further protrudes in a radiallyinward direction of the ring portion (53). The housing (23) includes amain body (23 a) that is a flange to which the fixed scroll (21) isfixed, and the main body (23 a) includes: a facing portion (71) having apredetermined thickness and having an orbiting scroll facing surface(70) being in contact with and facing (sliding on) the orbiting scroll(22); and an annular opening (72) formed around the orbiting scrollfacing surface (70) and movably housing the ring portion (53). The firstkey groove (61) is provided to the back surface (71 a) of the facingportion (71) (the surface opposite to the orbiting scroll facing surface(70)) so as to extend radially inwardly from the annular opening (72).

As illustrated in FIGS. 6 and 7, the first key groove (61) is preferablya groove opened on the back surface of the main body (23 a) that is theflange of the housing (23). In the following description of thisembodiment, the first key groove (61) is supposed to be a groove openedon the back surface of the main body (23 a), as illustrated in FIGS. 6and 7. In FIG. 7, the orbiting scroll facing surface (70) is providedwith a groove, i.e., a seal ring mounting groove (75) provided in asituation where a sealing ring is mounted to the orbiting scroll facingsurface (70).

The first key (54) includes a pair of first keys (54) opposed to eachother by 180° on the Oldham ring (50). The second key (55) includes apair of second keys (55) opposed to each other by 180° on the Oldhamring (50) so as to be at right angles with the first key (54).

In this embodiment, in FIGS. 8 and 9, the interval (A) between the pairof the first keys (54) is smaller than the outer diameter (B) of thefacing portion (71) of the housing (23), and the thickness (C) of thering portion (53) is larger than the thickness (D) of the facing portion(71) of the housing (23). The back surface of the facing portion (71) isa tilted surface (71 a) such that the thickness of the facing portion(71) increases toward the inner periphery of the facing portion (71).

According to such a configuration, as illustrated in FIG. 10, one firstkey (54) is inserted into one first key groove (61) from the annularopening (72) while the Oldham ring (50) is tilted, allowing one firstkey (54) to engage with the back surface (71 a) of the facing portion(71) as illustrated in FIG. 11. Then, the other first key (54) isinserted into the other first key groove (61). This allows for attachingthe Oldham ring (50) to the housing (23).

Operation

Next, it will be described how the scroll compressor (1) stated above isoperated.

First, if the electric motor (45) is driven, the drive shaft (40)rotates and the orbiting scroll (22) revolves relative to the fixedscroll (21). At that time, the Oldham ring (50) prevents the fixedscroll (21) from rotating on its axis.

Along with the revolution of the orbiting scroll (22), volumes of thecompression chambers (25 a. 25 b) increase and decrease repeatedly andperiodically. In the compression chambers (25 a, 25 b), the refrigerantin the refrigerant circuit is sucked from the suction pipe (14) througha suction passage (not shown) and the suction port (29) into thecompression chambers (25 a, 25 b) when the volume of a portion,communicating with the suction port (29), of the compression chambers(25 a, 25 b) is increased, and the refrigerant in the refrigerantcircuit is compressed and discharged from the discharge port (26) to thedischarge chamber (28) when the volume of a portion in which a suctionside is closed decreases. The refrigerant in the discharge chamber (28)is supplied from the discharge pipe (15) to the condenser in therefrigerant circuit, and is circulated in the refrigerant circuit. Then,the refrigerant in the discharge chamber (28) is sucked into the scrollcompressor (1), again.

Next, the operation of the Oldham ring (50) of this embodiment will bedescribed.

In this embodiment, the first key groove (61) formed in a positionadjacent to the back surface of the opposing surface (71) engages withthe first key (54) of the Oldham ring (50), allowing the Oldham ring(50) to operate. At that time, the first key (64) protrudes from thering portion (53) of the Oldham ring (50) toward the housing (23) andfurther protrudes in the radially inward direction of the ring portion(53). This can sufficiently increase the area of the sliding surfacebetween the first key (54) and the first key groove (61) to reduce acontact pressure of the key sliding surface. Also, the first key (54)protrudes in the radially inward direction of the Oldham ring (50), andthe outer periphery of the housing (23) does not have to be notched (seeFIG. 20), and the moment of the first key (54) can be reduced. Further,the first key groove (61) is formed in the position adjacent to the backside of the orbiting scroll facing surface (70) (in the positionadjacent to the back surface of the facing portion (71)), and thus, evenif a sealing ring (not illustrated) is used, the first key groove (61)does not hinder the formation of the sealing ring.

Also, according to this embodiment, the pair of first keys (54) areopposed to each other by 180° on the Oldham ring (50) to satisfy therelationship such that the interval (A) between the pair of the firstkeys (54) is smaller than the outer diameter (B) of the facing portion(71) of the housing (23) and the thickness (C) of the ring portion (53)is larger than the thickness (D) of the facing portion (71) of thehousing (23). Thus, as illustrated in FIGS. 10 and 11, the Oldham ring(50) can be easily attached to the housing (23) along an obliquedirection.

Also, the back surface of the facing portion (71) is the tilted surface(71 a), and thus, when the Oldham ring (50) is attached to the housing(23), the first key (54) can be easily inserted into the first keygroove (61). In this embodiment, the first key (54) engages with thefirst key groove (61) opened on the back surface of the flange (23 a) ofthe housing (23), allowing the Oldham ring (50) to operate.

Advantages of Embodiment

According to this embodiment, the first key (64) protrudes from the ringportion (53) of the Oldham ring (50) toward the housing (23) and furtherprotrudes in the radially inward direction of the ring portion (53).This can sufficiently increase the area of the sliding surface betweenthe first key (54) and the first key groove (61) to reduce a contactpressure of the key sliding surface. Therefore, this can contribute topreventing insufficient strength of the first key (54) of the Oldhamring (50).

Also, since the first key (54) protrudes in the radially inwarddirection of the Oldham ring (50), the outer periphery of the housing(23) does not have to be notched, and the moment of the first key (54)can be reduced. Therefore, this can contribute to preventing thestrength of the Oldham ring (50) from decreasing too much.

Further, the first key groove (61) is formed in the position adjacent tothe back side of the orbiting scroll facing surface (70) (in theposition adjacent to the back surface of the facing portion (71)), andthus, the first key groove (61) does not hinder the formation of thesealing ring (not illustrated). Therefore, this makes it possible to usethe seal ring (50) in a configuration in which the first key (54) andthe first key groove (61) engage with each other.

Also, according to this embodiment, the interval (A) between the pair ofthe first keys (54) is smaller than the outer diameter (B) of the facingportion (71) of the housing (23), and the thickness (C) of the ringportion (53) is larger than the thickness (D) of the facing portion (71)of the housing (23). Thus, as illustrated in FIGS. 10 and 11, the Oldhamring (50) can be easily attached to the housing (23) along an obliquedirection. Accordingly, the Oldham ring (50) does not have to be madelarge, making it possible to reduce the size of the mechanism.

Also, according to this embodiment, the back surface of the facingportion (71) is the tilted surface (71 a), and thus, when the Oldhamring (50) is attached to the housing (23), the first key (54) can beeasily inserted into the first key groove (61), improving ease ofattachment.

Also, the first key groove (61) according to this embodiment, which is agroove opened on the back surface of the main body (flange) (23 a) ofthe housing (23), can be easily formed.

Variations of Embodiment (First Variation)

As illustrated in FIG. 12, the facing portion (71) may have a plateshape with a constant thickness. Such a configuration also allows foreasily forming the first key groove (61) in the main body (23 a) of thehousing (23), and easily mounting the first key (54) in the first keygroove (61).

(Second Variation)

As illustrated in FIG. 13, the facing portion (71) may be configured asa separate member fixed to the main body (23 a) of the housing (23).Such a configuration also allows for easily forming the first key groove(61) in the main body (23 a) of the housing (23), and easily mountingthe first key (54) in the first key groove (61).

(Third Variation)

As illustrated in FIGS. 14 and 15, the first key groove (61) may be agroove opened on the outer peripheral surface of the main body (flange)(23 a) of the housing (23).

Also in such a configuration, the groove opened on the outer peripheralsurface of the main body (flange) (23 a) of the housing (23) whichfunctions as first key groove (61) can be easily formed.

Other Embodiments

The above-described embodiment may be modified as follows.

For example, in this embodiment, the interval (A) between the pair ofthe first keys (54) is set to be smaller than the outer diameter (B) ofthe facing portion (71) of the housing (23), and the thickness (C) ofthe ring portion (53) is set to be larger than the thickness (D) of thefacing portion(71) of the housing (23). However, these elements do notnecessarily have to be set as described above.

In the third variation of the embodiment, oil may remain in the firstkey groove (61) to prevent the first key (54) from moving smoothly. Itis therefore suitable that the housing (23) is provided with an oilremoving hole for removing oil from the first key groove (61),

According to this embodiment, the orbiting scroll facing surface (70) ofthe facing portion (71) of the housing (23) is in contact with and facesthe orbiting end plate (22 a) of the orbiting scroll (22) to slide onthe orbiting end plate (22 a). However, as illustrated in FIG. 16, thesealing ring (76) may be mounted in the sealing ring mounting groove(75) to allow the orbiting scroll facing surface (70) to be spaced apartfrom and face the orbiting end plate (22 a) of the orbiting scroll (22),and thus, the orbiting scroll facing surface (70) may be a surface notsliding on the orbiting end plate (22 a). Even if the orbiting scrollfacing surface (70) is not the surface sliding on the orbiting scroll(22), the above configuration of the present disclosure allows the firstkey groove (61) not to hinder the formation of the sealing ring (notillustrated).

Note that the foregoing description of the embodiments is a merelypreferred example in nature, and is not intended to limit the scope,application, or uses of the present disclosure.

INDUSTRIAL APPLICABILITY

As can be seen from the foregoing description, the present disclosure isuseful for, in a scroll compressor provided with a compression mechanismhaving a fixed scroll and an orbiting scroll, a structure of allowingthe compression mechanism to hold an Oldham ring that is a mechanismpreventing the orbiting scroll from rotating on its axis.

DESCRIPTION OF REFERENCE CHARACTERS

1 Scroll Compressor

21 Fixed Scroll

22 Orbiting Scroll

23 Housing

23 a Flange (Body)

40 Drive Shaft

50 Oldham Ring

51 First Key Mechanism

52 Second Key Mechanism

53 Ring Portion

54 First Key

61 First Key Groove

70 Orbiting Scroll Facing Surface

71 Facing Portion

71 a Tilted Surface

72 Annular Opening

1. A scroll compressor comprising: a housing into which a drive shaft isinserted; an Oldham ring configured to be slidable on the housing by afirst key mechanism in a first direction perpendicular to an axialcenter of the drive shaft; a fixed scroll fixed to the housing; and anorbiting scroll meshing with the fixed scroll and configured to beslidable on the Oldham ring by a second key mechanism in a seconddirection perpendicular to the axial center of the drive shaft, thefirst key mechanism including a first key provided to the Oldham ringand a first key groove formed in the housing, the first key protrudesfrom a ring portion of the Oldham ring toward the housing, and furtherprotrudes in a radially inward direction from the ring portion, thehousing including a flange to which the fixed scroll is fixed and whichincludes a facing portion having a predetermined thickness and having anorbiting scroll facing surface facing the orbiting scroll, and anannular opening formed around the orbiting scroll facing surface andmovably housing the ring portion, and the first key groove being formedat a position adjacent to a back surface of the facing portion oppositeto the orbiting scroll facing surface so as to extend radially inwardlyfrom the annular opening.
 2. The scroll compressor of claim 1, whereinthe first key includes a pair of first keys opposed to each other bybeing disposed 180° apart on the Oldham ring, and an interval betweenthe pair of the first keys is smaller than an outer diameter of thefacing portion of the housing, and a thickness of the ring portion islarger than a thickness of the facing portion of the housing.
 3. Thescroll compressor of claim 1, wherein the back surface of the facingportion is a tilted surface such that a thickness of the facing portionincreases toward an inner periphery of the facing portion.
 4. The scrollcompressor of claim 1, wherein the first key groove is opened on a backsurface of the flange of the housing.
 5. The scroll compressor of claim1, wherein the first key groove is opened on an outer peripheral surfaceof the flange of the housing.
 6. The scroll compressor of claim 1,wherein the facing portion is configured as a separate member differentfrom the housing and fixed to a main body of the housing.
 7. The scrollcompressor of claim 2, wherein the hack surface of the facing portion isa tilted surface such that a thickness of the facing portion increasestoward an inner periphery of the facing portion.
 8. The scrollcompressor of claim 2, wherein the first key groove is opened on a backsurface of the flange of the sing.
 9. The scroll compressor of claim 2,wherein the first key groove is opened on an outer peripheral surface ofthe flange of the housing.
 10. The scroll compressor of claim 2, whereinthe facing portion is configured as a separate member different from thehousing and fixed to a main body of the housing.
 11. The scrollcompressor of claim 3, wherein the first key groove is opened on a backsurface of the flange of the housing.
 12. The scroll compressor of claim3, wherein the first key groove is opened on an outer peripheral surfaceof the flange of the housing.
 13. The scroll compressor of claim 3,wherein the facing portion is configured as a separate member differentfrom the housing and fixed to a main body of the housing.